/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/MeshBones.h
Return an array of indices into the bone attribute arrays of all the children of the bone. Optionally, recursively add all grandchildren via a breadth-first search.
static bool GetBoneChildren ( const [FDynamicMesh3](API\Runtime\GeometryCore\DynamicMesh\FDynamicMesh3) & Mesh, int32 BoneIndex, [TArray](API\Runtime\Core\Containers\TArray)< int32 > & ChildrenIndices, bool bRecursive )